Sample Size Considerations for Multilevel Surveys

Social and economic data commonly have a nested structure (for example, households nested within neighborhoods). Recently techniques and computer programs have become available for dealing with such data, permitting the formulation of explicit multilevel models with hypotheses about effects occurring at each level and across levels. If data users are planning to analyze survey data using multilevel models rather than concentrating on means, totals, and proportions, this needs to be accounted for in the survey design. The implications for determining sample sizes (for example, the number of neighborhoods in the sample and the number of households sampled within each neighborhood) are explored.